Inherited metabolic diseases presenting with neonatal seizures and key screening investigations
| Diagnosis | Sample | Investigation |
|---|---|---|
| Pyridoxine-dependent seizures* | Urine, CSF or plasma | α-Amino adipic semialdehyde |
| Pipecolic acid | ||
| Pyridoxal phosphate-dependent seizures* | CSF | Pyridoxal phosphate |
| 3-Phosphoglycerate dehydrogenase deficiency* | CSF | Serine |
| GLUT-1deficiency* | CSF and plasma simultaneous | Glucose (low CSF/plasma ratio <0.46) |
| Sample plasma first to avoid stress-related elevation and false-positive result | ||
| Biotinidase deficiency* | Plasma | Biotinidase |
| Non-ketotic hyperglycinaemia | CSF and plasma | Amino acids (raised CSF/plasma glycine ratio >0.09) |
| Molybdenum cofactor deficiency and sulphite oxidase deficiency | Urine (fresh) | Sulphite dipstick |
| Purine studies | ||
| Purine disorders | Urine | Purine studies |
| Peroxisomal disorders | Plasma | Very long-chain fatty acids |
↵* Effective treatment available.
CSF, cerebrospinal fluid; GLUT-1, glucose transporter 1.